It has been found desirable to provide certain automated lithographic duplicators with ink of low viscosity and also to do this in such manner that the temperature rise of the ink in the fountain due to working of the ink is minimized. This is accomplished by a radially presented blade which acts to doctor a thick film of ink onto the surface of the fountain roller and at the same time to support the body of ink in the fountain. The gap between the blade and the fountain roller must be accurately adjusted to close tolerances to give a very small gap in order to prevent leakage of the low viscosity ink when the machine is not running.